Low-frequency acoustics in solid He-4 at low temperature

Article

关键词: HELIUM CRYSTALS;    HCP HE-4;    SOUND PROPAGATION;    DISLOCATIONS;    VELOCITY;    MOTION;   

DOI  :  10.1103/PhysRevB.80.140504

来源: SCIE

【 摘 要 】

The elastic properties of hcp He-4 samples have been investigated using low-frequency (20 Hz to 20 kHz) high sensitivity sound transducers. In agreement with the findings of other workers, most samples studied grew very significantly stiffer at low temperature; Poisson's ratio nu was observed to increase from 0.28 below 20 mK to similar to 0.35 at 0.7 K. The span of the variation in nu varies from sample to sample according to their thermal and mechanical history. Crystals carefully grown at the melting curve show a different behavior, the change in nu taking place at lower T and being more abrupt.

【 授权许可】

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